Examples of self-propelled construction machines specifically include rollers, landfill compactors, road milling machines, recyclers, ground stabilizers and stationary and mobile crushers. Such machines comprise an internal combustion engine as the main drive, by means of which the travelling mechanism, a milling rotor and further working devices are driven. The milling rotor is lowered in working operation to a working position and it is operated at an operating speed.
In the case of maintenance and mounting work on the milling rotor of a milling machine, e.g. during the replacement of milling teeth, it is necessary to move the milling rotor slowly and step-by-step with small angular offset or continuously so that an operator has full access to the entire cylinder jacket, even when the milling rotor is installed in the milling machine. The first drive unit, if it is the main drive, is not suitable for this purpose, especially due to the high rotational speed and torque. For safety reasons, the use of the main drive is not permissible, and it must always be switched off during maintenance and mounting work. Therefore, this work is performed using a second drive unit as an auxiliary drive. The known methods of activation of this auxiliary drive with simultaneous deactivation of the main drive have turned out to be relatively complicated. An example of such an apparatus is known from DE 10031195 C1.
The invention is based on the object of providing an apparatus of the kind mentioned above which requires little installation space in the construction machine.
This object is achieved in such a way that the clutch is provided with a fixed side and, on the output side, with an axially displaceable side which is displaceable between an engaged position and a disengaged position, such that the axially displaceable side is simultaneously also the engaging and disengaging part of a shiftable transmission, the fixed part of which is driven by the auxiliary drive, with the transmission and the clutch being engaged and disengaged in a selective fashion via the axially displaceable side of the clutch.